What Tawera Kerr-Barlow originally thought was an aggravation of wisdom tooth pain he had suffered over the past seven days has sidelined the Chiefs halfback for six weeks.

The two-test All Black had his swollen jaw x-rayed on Saturday morning and it turned out to be broken after taking a bang in the mouth during last Friday night's 19-7 Super Rugby victory over the Highlanders at Waikato Stadium.

That victory consolidated the Chiefs' lead in the New Zealand Conference and their second placing overall.

But the loss of Kerr-Barlow is a blow, though somewhat softened by the return of Brendon Leonard from a broken cheekbone suffered in pre-season play.

"[Kerr-Barlow's] face was swollen after the game - he obviously got a bang around there - and it had been sore in the week leading into it," Chiefs head coach Dave Rennie said yesterday.

"He had a scan the day before and there was nothing visible other than something around his wisdom tooth."

So Kerr-Barlow played 80 minutes, making a lot of tackles, and was seen getting treatment a couple of times for a sore and bleeding mouth, but it was not until Saturday's x-ray that the extent of the damage was realised.

Leonard has been pulled from the Chiefs' development team, who thrashed Tonga A 50-18 in a Pacific Nations Cup match on Saturday, to ensure the side has two fit halfbacks for this weekend's clash with the Blues in Mt Maunganui.

''It's good timing with Harry [Leonard] coming back in but it's tough for Tawera and he's pretty gutted,'' Rennie said.

Leonard is in top fitness, having been able to train in the gym while sidelined by the injury. Rennie said there were a ''lot of sore bodies'' after the short turnaround between games and the travel back from South Africa and he gave the team a rare weekend off, apart from the Saturday morning recovery session.

First-five Aaron Cruden was one looking forward to the time off to freshen up, admitting he was exhausted and sore after Friday night's match that followed two games in South Africa and then the trip back.

''It takes its toll really,'' said Cruden.

''You sort of head into the game telling yourself you're feeling fresh and you're feeling good but after the final whistle you saw the reaction of the boys - we were pretty happy the ref had called time.

''It was a pretty gutsy performance I think. It was hard to get our game going, our set-piece struggled at times, so to not play to our potential but still get a win was pretty good.''